Decays of the f0(1370) scalar glueball candidate in pp Central Exclusive Production (CEP) and in antiproton annihilations at rest

Abstract

Decays into two charged pions of the f0(1370) are the main source of an isolated structure localized between 1.2 and 1.5 GeV in the two charged pions mass spectrum measured in pp Central Exclusive Production (CEP) at 200 GeV at very low four momentum transfer ltl by the STAR experiment. These data confirm in the two charged pions decay channel the existence of the f0(1370) as an isolated well identified structure previously observed in K+K-, KsKs, 4 charged pions, two charged and two neutral pions and 4 neutral pions decays measured in antiproton annihilations at rest. The ensemble of these data point at a high gluon content of the f0(1370). CEP interactions at higher energies favour production of 0++ and 2++ mesons. Selection of events with lower ltl at both proton vertices suppresses 2++ structures. LHC runs dedicated to pp CEP measurements at low ltl could then provide a unique source of all the low energy scalars. This would make it clear if and where scalar gluonium is resident and the nature (composition in terms of quarks, antiquarks and gluons) of f0(500), f0(980), f0(1370), f0(1500) and f0(1710).